CRISP behind the UN's World Urbanization Prospects 2025
18 November 2025
On 18 November 2025 the Population Division of UN DESA published World Urbanization Prospects 2025. It covers 237 countries and more than 12,000 cities. The localised projections of population and built-up area in it were produced with CRISP, the model we developed with the Joint Research Centre of the European Commission and the Vrije Universiteit Amsterdam.
This edition changed method. Earlier editions let every country apply its own definition of a city, which made international comparison unreliable. This one applies the degree of urbanisation, a single density and population threshold used everywhere, so cities, towns and rural areas mean the same thing in every country. CRISP carries that classification forward in time by downscaling national projections to a one-kilometre grid.
The change of method also explains the headline most news outlets picked up. Jakarta is now the world's most populous city, ahead of Dhaka and Tokyo, where the 2018 edition still had Tokyo first. The city did not suddenly grow; it is measured differently, as a built-up area rather than as an administrative boundary.
What the projections show
- Between 1975 and 2025, built-up land grew almost twice as fast as the world's population. Built-up land per person rose from 44 to 63 square metres.
- The number of cities doubled, from around 6,000 in 1975 to some 12,000 today, and the number with more than ten million inhabitants went from 8 to 33.
- Most urban residents live in cities of between 50,000 and 250,000 people, not in the megacities that get the attention.
- Around 3,000 cities lost population between 2015 and 2025, Mexico City and Chengdu among them. Growth and decline happen at the same time.
- Seven countries account for more than half of the 982 million new city dwellers expected by 2050.
Read further
The Joint Research Centre summarised the built-up findings in the world's constructed areas are expanding twice as fast as its population, and the EU Space Programme collected seven things we learned from the report. The Vrije Universiteit described the contribution of the model, and the UN issued its own press release. The release was covered around the world, including by the Guardian, Al Jazeera, NBC News and, in the Netherlands, the NOS.
The gridded results are open data, published by the Joint Research Centre in the GHSL data package. The model is documented at geodms.nl/crisp.